Collimator



J., MORI-:LLE

COLLIMATOR March 9, l1943.

Filed Sept. l2, 1939` ungarn `lamented Mar. 9, 1943- UNlTED .STATEsi PATENT oFFICa 'o COLLIMATOB. i Jules Morelle, Paris, France; vested in the Alien Property Custodian Application September 12, 1939, Serial No. 294,523

' In France December 12, 1939 1 0mm. (ci. 11s- 2.3)

Itis often necessary, more particularly in aiming devices, to determine a xed direction and this is generally obtained by means of apparatuses termed collimators and comprising essentially an object glass, a reticle disposed at, the focus thereof and a semlreecting glass plate.A

But it is also often required to determine not only a principal direction but also `auxiliary directions forming therewith substantial angles; in said case it becomes necessary to use an object glass without aberration and 'such an object glass is always complicated and comprises at least three lenses which absorb a substantial part of the light. y

The present invention has for its object a collimator avoiding said drawbacks and allowing to determine besides a principal direction, auxillary directions forming substantial angles therewith, and comprising a concave mirror; a reticle disposed in the focal surface thereof, means for illuminating said reticle and means for displacing a mark throughout the area thereof; a semireilecting glass plate so disposed that it reiiects in the observers eye the infinitely removed image of the reticle produced by reflection on the concave mirror.

Another object of the invention is a form of execution of such a collimator wherein the reticle is an opaque plate, rotatable round the mirror axis and provided with a spherical slit the centre of which is the same as that of the mirror; a small screen is movable along said slit and .its image appears to the observer as an infinitely removed black .point determining the desired direction.

In order that the invention may be clearly understood andreadily carried into eect a col-l centre in C and the focus in F equidistant from S and C; 2 is a spherical reticle concentric to the ymirror l' and disposed at the focus F; 3 is a semitransparent glass plate and in C is a luminous surface 4 illuminating the reticle 2.

The light beam emitted by 4 and passing through point F of the reticle passes, at least in Part, across the glass plate 3, is reected further on the concave mirror 'I and forms then a cylindrical beam, a part of this latter is. reflected 'on the glass plate 3 and becomesa cylindrical beam the axis of which is 3:32' land the basis an image 4' of the luminous surface 4; said last mentioned beam impinging in the observers eye, this latter perceives an infinitely removed image of the point F, by instance if the reticle was opaque and provided only with a small aperture disposed at F, said observer would see an infinitely removed punctiform luminous spot in the direction rcx', said spot determining the principal direction.

If the aperture in the opaque reticle was made in F', instead of F, the working would be the same except thaty the luminous spot would be seen in the direction gf'" instead of zx' and would thus determine the auxiliary direction 'llfl. y n

It would be possible to use as reticle a cylindrical plate the axis of which would pass through iniinitely'removed luminous line, image of the illuminated slit, said line being interrupted at a certain point by the image of the screen, said interruption indicating the required auxiliary direction such as :r":c' of Figure l.

Figures 2 and 3 illustrate a form of execution of the collimator the Working of which has been disclosed hereinabove. The reference letters and numbers correspond to the same parts on the three figures.

The spherical mirror I and the semireecting glassplate 3 are arranged in a casing 5, in the upper part of which is provided acircular opening the center of which is on the axis CS of the mirror. In said opening a ring 6 may rotate, in

the inside of said ring is fixed a plate shaped as a cylinder whose axis passes through C. A slit 'l is cut in said plate in the plane perpendicular to the axis thereof passing through CS, and before said s lit a small screen 8 may be displaced so that it covers only a very slight part thereof, said screen is supported by an arm 9 rotatably mounted on a stem il fixed on the ring 6; the rotation axis of the arm 9 passes through C and said arm may be rotated by means of a knob I3.

It will be understood that if we move the screen by means of knob I3 and if We rotate the ring round CS it is possible to bring said screen in any desired point of the area enclosed by the ring. and therefore to determine an auxiliary direction such' as :z:":c forming anydesired angle with the principal direction.

On the stem Il is also xed the light source l, constituted say by a light spreading surface i1- lu.ninated by a lamp, or by the imageof another luminous surface produced by a suitable optic system.

Modications may be brought to the above disclosed device without widening the scope of the invention; say the mirror may be made of glass the rear surface of which is made' reflecting, the

, curvatures of both surfaces being different.

The spherical mirror might be also replaced by a parabolic one the point F being the focus of the parabola meridian curve o f said mirror and the center C being, that of the osculating circle at the vertex of said parabola.

What I claim is:

A collimatory adapted to determine exactly not 25 only a principal direction but also auxiliary directions forming substantial angles with said principal direction, comprising: a spherical concave irror, an opaque plate able to rotate round said mirror axis, said plate being shaped as a revolution cylinder the radius of which is equal to the half of the radius of said mirror. and said vcylindrical plate being disposed so that its axisv passes through the center of the mirror and is perpendicular to the axis thereof, said plate being also provided with a slit'the plane of which is perpendicular to its axis: a screen adapted to hide a part of said slit; a light source disposed at the center of the spherical mirror and adapted to illuminate said slit: a semitransparent glass plate so disposed between the slit and the spherical mirror that it reflects in the observers eye the infiinitely removed luminous image of the slit partially hidden by the screen formed by the `spherical concave mirror: means for displacing said screen before said slit so that its image. after `reflection in the spherical mirror is seen by the observer in the desired auxiliary direction.

JULES MORELLE. 

